No engine drone next to the queue, no fumes near the cups. Tell Wattonomy your machines and it sizes the battery and inverter to start your espresso machine and carry a full market day, then hands you the wiring and parts to build it safely.
A real Wattonomy output — a single-group coffee cart
System
24 V
Battery
10.24 kWh
Solar
1200 W
Inverter
MP-II 24/5000 12
SmartSolar 100/501×
200W solar panel6×
Battery → inverter cable7×
Battery → inverter fuse1×
Wire & fuse sizes follow ABYC E-11 — each conductor carries its fuse and stays under a 3% voltage drop.
Built to ABYC standards
Gauge · fuse · volt-drop sized
Every spec sourced
A 1,500W espresso machine on a guessed inverter is a dead cart.
Espresso boilers draw their full load the instant they heat, and an undersized inverter simply cuts out. Wattonomy sizes the inverter for that surge, the bank for a real trading day, and every cable to carry its fuse — to ABYC E-11 — so the cart stays up from first flat white to last.
What a coffee cart has to get right.
Four numbers that decide whether the cart feels professional or stressful.
Trading-day energy
Espresso idle-hold and pulls, grinder, a small fridge, lights and the card reader — summed as real Wh for your day.
Inverter for surge
Sized to start the espresso machine, not just run it — with headroom so it never trips at the worst moment.
Battery to match
LiFePO4 sized to carry the day on an honest depth-of-discharge, topped by solar and charge-while-you-drive.
Cables & fuses
Every gauge, fuse and AIC matched to the load and your real run lengths, with the espresso machine on its own circuit.
What you walk away with — free
A validated system sized to your equipment — not a one-size kit
A clean wiring diagram with every cable gauge and fuse spelled out
Cable & fuse sizing with the voltage-drop checked for your run lengths
A shoppable parts list, each line traceable to ABYC or Victron specs
Building it for real? Unlock the build binder.
Free gets you a safe, correctly-sized design. The build binder gets you the documents to build it right — and prove it's right.
Printable wiring diagram, yours to keep & tape inside the cart
Full parts list, every line sourced
The volt-drop & fusing calculation trail — the "why" behind every spec
The build binder is a one-time unlock — no subscription, no auto-renew.
Questions
What size battery and inverter for a coffee cart?
Enter your real machines and the tool sizes both — a single-group cart typically lands on a few kWh of LiFePO4 and a 2,000–3,000W inverter, but it sizes to your exact loads, including the start-up surge.
Can a battery really run an espresso machine?
A single-group 120V machine on a properly sized inverter and bank, yes. The tool sizes for the boiler’s surge and puts it on its own circuit; a two-group machine is a 240V job it will flag rather than fake.
How long will it last between charges?
The tool sizes the bank to your trading day and shows the runtime, plus how solar and driving top it back up — design for the busy day, not the quiet one.
Do I need an account?
No. Design the whole system free, no email required. Accounts are only for saving builds or the printable build binder.
Is this just trying to sell me a kit?
No. The parts list is vendor-neutral and standards-referenced — buy the components anywhere. We make the design, not the markup.
The standards we build to
Plain version: these are the recognized rulebooks your design is sized against, so the numbers hold up to a surveyor, an inspector or an insurer.
ABYC E-11The US standard for AC & DC wiring on boats — what a surveyor or insurer actually checks.
Wattonomy applies these standards in its calculations. It is not certified, sponsored or endorsed by ABYC, ISO, NFPA or Victron — it sizes your design to meet what they require, and shows the working.
Sized and checked to ABYC E-11. Last reviewed June 2026 — see the full methodology for the exact rules behind every number and how each design is validated.
Built by anABYC Certified Master Technician